spm

Use printf not echo

diff --git a/tpm b/tpm
@@ -31,13 +31,13 @@ fi
 ### Helper ###
 
 abort() {
-  echo "${1}" 1>&2
+  printf '%s\n' "${1}" 1>&2
   exit 1
 }
 
 readpw() {
   if [ -t 0 ]; then
-    printf "%s" "${1}"
+    printf '%s' "${1}"
     stty -echo
   fi
 

@@ -46,7 +46,7 @@ readpw() {
 }
 
 usage() {
-  echo "USAGE: tpm show|insert|list|help [ENTRY|GROUP]"
+  printf 'USAGE: tpm show|insert|list|help [ENTRY|GROUP]\n'
 }
 
 ### Commands ###

@@ -59,7 +59,7 @@ insert() {
 
   password=""
   readpw "Password for '${1}': " password
-  [ -t 0 ] && printf "\n"
+  [ -t 0 ] && printf '\n'
 
   [ -z "${password}" ] && abort "You didn't specify a password."
 

@@ -76,7 +76,7 @@ list() {
 
   tree --noreport -l -C -- "${STORE_DIR}/${1}" \
     | sed 's/.gpg$//g'
-  echo
+  printf '\n'
 }
 
 remove() {